Rapid thermal anneal (RTA) is a common process in semiconductor fabrication. When rapid thermal anneal process is over, wafers are unloaded from the rapid thermal anneal tool to be transferred to other processing tools. At this point of time, the wafers are at a high temperature, e.g., 300° C. However the wafer carrier of the wafer transfer equipment is at room temperature, resulting in a large temperature difference between the wafer and the wafer transfer equipment, which may induce a high thermal stress inside the wafer, reduce its mechanical strength, and even cause the wafer to break. The case is worse in production lines for large-size wafers, e.g., the world's largest 12-inch wafers, or further 16-inch wafers.
Therefore, new wafer transfer equipment and wafer transfer method are desired, to reduce the temperature difference between the wafer and the transfer equipment, and decrease the thermal stress inside the wafer, thereby ensuring the completeness of the wafer.